Pronóstico: S&P 500 (SPX) Up or Down on June 29?

Platform comparison

Market context

The S&P 500 closes today, Monday 29 June 2026, and the market resolves based on whether that final price is higher or lower than Friday’s close. Polymarket prices this contract at 97% YES for an “Up” outcome, reflecting near-certainty in the crowd that the index will finish higher than the prior session.

Historically, Monday closes in late June have often followed Friday’s trend unless a weekend catalyst intervenes. In 2025, the SPX rose 0.4% on the last Monday of June after a flat Friday, while in 2024 it fell 0.2% following a 0.6% drop. The current 97% probability is unusually high for a single-day move, suggesting traders see little risk of a reversal despite the index’s recent 2.57% monthly decline [1].

Traders should watch the Federal Reserve’s June meeting summary, released this week, and any surprise comments from Chair Powell on inflation or rate cuts. The gold price’s 2026-largest drop to $3,972 signals evaporating war premiums, which may shift risk appetite toward equities [3]. Analyst Andrew Pancholi notes key downside targets at 7,313 and 7,122, but the current momentum leans upward unless macro data disappoints [2]. On-chain, USDC settlements on Polygon via conditional tokens will execute automatically once the official close is confirmed.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

Methodologically we separate two layers: the live probability (Polymarket mid-price) and the platform attributes (fee, KYC, settlement currency, payment rails). That keeps the comparison honest — a single canonical probability across the row, with the venue-by-venue trade-offs spelt out in the columns next to it.

Resolution & payout

Settlement runs on-chain. Polymarket's contract logic separates YES and NO shares as conditional tokens; at resolution the winning share lifts to $1.00 and the losing one to $0. The outcome input comes from the UMA Optimistic Oracle, which secures against bad resolution with a bond + dispute window.

Once finalised, the smart contract pays USDC to the holders' wallets within minutes — no withdrawal fees beyond Polygon network gas. Kalshi settles in USD via CFTC clearance, Betfair in account currency net of commission, Manifold in play-money mana with no cash-out.

FAQ

Where can I trade this market with the lowest fees?

Polymarket is geo-blocked in the US/UK/EU. The easiest 0%-fee broker into the same order book is Polymarket Qué Es. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

Is this market available outside the US?

Polymarket itself is geo-blocked in the US/UK/EU. Always check the legal status of prediction markets in your jurisdiction before trading.

What does Polymarket cost to trade?

Polymarket itself charges 0% — the only cost is the Polygon network fee, typically under $0.01 per transaction. Off-chain venues like Kalshi or Betfair charge 2-7% commission.

Do I need to KYC for this market?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like Polymarket Qué Es trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.

How reliable are the quoted odds?

The YES/NO percentages are the live mid-prices of the Polymarket order book. On deep markets they move every few seconds; on thinner ones you'll see short plateaus.